1. Field of the Invention
The present invention relates to recording and reproducing apparatus for recording and transmitting video signals with an efficient coding.
2. Description of the Prior Art
Video compression coding is known as a technique used for reducing a data quantity of video signals. In a known video compression coding, a block is composed of neighboring pixels, and video signals in each block are compressed by orthogonal transformation. Orthogonal components obtained by the orthogonal transformation are processed with a variable length coding. Then, they are recorded or transmitted.
The recorded orthogonal components of variable length coding is decoded on reproduction. When an error happens on reproducing the recorded video signals, error propagation occurs due to variable length coding. Therefore, an error of one bit causes large deterioration of image quality on reproduction. If a record area of fixed length is assigned for each block, error propagation is suppressed at minimum. However, when reproduced data are recorded again, the data are processed with a variable length decoding, errors are corrected and the corrected data are recorded with a variable length coding. Then, a scale of a recording circuit therefor increases because it is needed to carry out variable length decoding and variable length coding at the same time.